I'm not aware of one. Most have used the GM columns, or an aftermarket one. The GM's wiring harness is pretty user friendly. Don't know about the Mustang's.
Regardless, you'll need some type of column bracket to support it at the dashboard. Also, at the firewall I used this little bracket from Speedway. Works great.
View attachment 22427
I think the upper part you refer to is part of the swinging pedal mount that 3676 bolt to.
Okay got ya, Turn signal switch mounting plate. Ford par t#C5DZ-3511-A
Looks like it fits into the 'cup' at the top of the shaft just behind the wheel (PN 3790). It all probably functions to help support the shaft and center it. Without the cup part it probably doesn't help with supporting the column.
heck, that's a better diagram than i found for the mustang. i would imagine the systems operate pretty much identically and it looks like that part i'm asking about may be pretty important indeed enven if i don't use the factory horn and directionals. thanks!I don't know if this might help. I think my steering column is from a 1967 Ford F100,
so it might be very similar.
View attachment 22436
View attachment 22435
View attachment 22434
I also have a wiring diagram that I used when wiring my car.
.
I found, and you probably will too, that during the course of building your bucket, you’re going to buy any number of things you’ll never use. You see something, you think you can use it, you buy it and then change your design direction! I’m sure others have done that, too.